Harman Kardon AVR 520, Service Manual

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harman/kardon
Service Bulletin
Service bulletin # H/K2003-07 Sept. 2003
Warranty labor rate: MINOR repair
To: All harman/kardon Service Centers
Model: AVR110/210/310/510, AVR120/220; AVR320/520
Subject: Various Complaints
For Complaints:
NO AUDIO
NOISE
INTERMITTENT NOISE
INTERMITENT AUDIO
Possible Solution:
Voltages may be too high on DSP Buffer IC or DSP IC
All modifications are done to the DSP board.
AVR110/210/310/510
AVR120/220
Remove BD5 and replace with two 1N4148 diodes in series.
Remove R43 and R90 (3.3
Ω
) and replace each with a 1N4148 diode.
(See diagram Page 2 for location and polarity)
AVR320/520
Remove BD25 and replace with two 1N4148 diodes in series.
(See diagram Page 2 for location and polarity)
In all cases the 1N4148 diode(s) you need to add should be normal 2-lead axial components, like h/k
part# 13-0482 or equivalent (not SMD devices).
AVR520
harman/kardon
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